SPRINGFIELD, Mass. (WWLP) – A massive fire at a former industrial building in Springfield’s Mason Square neighborhood is out after burning for about 24 hours, and now investigators are trying to figure out a cause.

Springfield Deputy Fire Chief Glenn Guyer told 22News that firefighters put out the last of the fire at 140 Wilbraham Avenue during the mid-morning hours Tuesday. State troopers then went inside to investigate. There is no official word yet as to what started the fire.

Firefighters were first called to the building at around 9:30 Tuesday morning, though Dennis Leger, aide to the fire commissioner, said it is believed the fire had been burning for a while before they were notified. After about an hour, flames began coming out of the roof of the building’s landmark tower, and smoke could be seen from all across the neighborhood. Firefighters continued their work through the day and into the night and early morning hours.

Guyer said that two firefighters were injured Monday, one from heat exhaustion and one with a lower back injury. Both were taken to the hospital, but have since been released.

He told 22News that crews from Associated Building Wreckers are now tearing down the fire-damaged portion of the building. While the fire was burning on Monday, they were called in to knock down walls to separate the portion of the building that was burning from the other parts of the structure that had yet to catch fire.

The Wilbraham Avenue building is the former home of the Massachusetts Career Development Institute (MCDI), a job training center, which closed in 2013.